Power conversion circuits can include transformers or other components that isolate a primary side from a secondary side when the power sources or electrical loads on either side of the power conversion circuit have different ground potentials. U.S. Patent Application Publication 2015/0326105 to Pan et al describes a pulsating current ripple cancelling circuit for cancelling high-frequency current ripples with a ripple cancelling transformer coupled to a high frequency transformer and each respectively coupled to direct coupling blocking capacitors.